Egypt's President Hosni Mubarak has handed his powers over to his vice president but refuses to step down outright or leave the country.

The move means he will retain the title of President and ensure regime control over the reform process.

Stunned protesters in central Cairo who demand his resignation waved their shoes in contempt and shouted: "Leave, leave, leave."

The crowd in Tahrir Square had swollen to several hundred thousand in expectation that Mr Mubarak would announce in his address to the nation that he was stepping down. Instead, they watched in silence, slapping their foreheads in anger and disbelief. Some burst into tears. After he finished, they broke out into chants for him to go.

Immediately after Mr Mubarak's speech, Vice President Omar Suleiman called on the protesters to "go home" and asked Egyptians to "unite and look to the future".

The pair of addresses followed a series of dramatic events this evening which had raised expectations that Mr Mubarak was about to announce his resignation.

In a surprise step, the military announced on state TV that its Supreme Council was in permanent session in scenes which suggested that the armed forces were taking control, perhaps to ensure Mr Mubarak went.

The top general for the Cairo area told protesters in the square that "all their demands" would be satisfied, and the demonstrators lifted him on their shoulders, believing that meant Mr Mubarak's resignation.

Instead, the President went on air several hours later to deliver a firm 15-minute address which suggested that little has changed. Mr Mubarak said the demands of protesters for democracy are just and legitimate but vowed to stay "until power is handed over to those elected in September by the people in free and fair elections in which all the guarantees of transparencies will be secured".

Mr Suleiman was already leading the regime's efforts to deal with the crisis, but the announcement gives him official powers.